A new aramid/epoxy laminate for surface mount technology

A novel aramid/epoxy laminate for use in advanced surface mount technology was developed. The laminate consists of paper from PPDETA (poly-p-phenylene/3,4´-diphenylether terephthalamide) and epoxy resin with high purity and high temperature resistance. Since the laminate is designed and processed to have few impurities, high glass transition temperature, and high dimensional stability, the laminate can be used as a substrate for leadless ceramic chip carriers, COB, pin grid arrays, and other advanced surface mount technologies. Excellent reliability of the laminate with respect to electromigration between surface conductors, between plated-through barrels, and between opposed conductors is demonstrated. This behavior is related to the high purity and high temperature resistance of both the reinforcement material and the resin. The short life of through-hole plating in thermal shocks is improved by the use of a novel plating technology and a composite structure. Applications to multilayer boards and laminates with a low dielectric constant are also being investigated